Musical string instrument



Oct. 14, 1941; R. RUF 2,429,138

MUS ICAL STRING INSTRUMENT Filed Ju ne 8, 1944 2 Sheets-Sheet 1 NYORMAL PLUCKING RETURN NORMAL 44 42) 45 $4 4544 45 45 P v k 50 50 27 so 1 #50 L 1 II Y I INVENTOR.

ROBERT RUF' BAY ATTORNEY Oct. 14, 1947. R RUF 2,429,138

MUSICAL STRING INSTRUMENT Filed June 8, 1944 2 Sheets-Sheet 2 INVENTOR. ROBERT RUF ATTORNEY Patented Oct. 14, 1947 UNITED STATES PATENT OFFICE MUSICAL. STRING INSTRUMENT Robert But, Chicago, Ill. Application June 8, 1944, Serial No. 539,230

16 Claims.

This invention relates to key controlled musical string instruments, for example, of the guitar or mandolin type and the; like, provided with fret control, string plucking, and volume control means.

The frets, that is, the stationary ridges or bars underneath. the strings on the finger-board are provided for the purpose of determining the vibrating length ofthe strings in accordanoewith notes to be played. In manually operated instruments of this type the strings are depressed against the frets by the fingers of one hand of the player; finger-plucking of the correspondingstrings at the sounding-board or box; at the opposite end of the finger-board, by the fingers of the other hand of the player, produces the sounds in accordance with the. notes set on the frets. The operation is strenuous, even for seasoned players, and is productive of fatigue; it lessens the sensitivity and dexterity of the fingers and thus destroys the touch that is required for good playing. Many prospective players abandon practice for these reasons, and are deprived of the benefits that come with the ability to play an instrument. Such manual operation requires the. use of the hands for diiferent purposes, string control and plucking, respectively, and therefore prevents accompaniment. The range of use of the instrument is thus restricted.

The principal object of the invention is con-. cerned with the provision of means adapted for attachment to an instrument of the type noted above, which includes a keyboard and a stringplucking device, so constructed and arranged that the instrument can be played by operating the keys, using the fingers of both hands. The finger control for the frets and the finger-plucking of the strings are eliminated. The player can produce melody as well as accompaniment. The finger-board of the new instrument is. provided with a support or hook for engagement with the shoulder of the player, and with a chin-controlled lever for adjusting the volume. Special features of the invention relate to structural and functional details, with the object of keeping the mechanism as simple as possible, and to the provision of elastic actuating members which contact the strings at the fretsand pluck the strings at the sound box in sucha manner as to imitate the finger touch of an experienced player, thus avoiding harshand distorted notes.

The invention is described below with reference to the accompanying drawings, wherein Fig. 1 shows a plan top. view of an embodimentofthe new string instrument;

Fig. 2 is a side view of the instrument shown in Fi 1;

Fig. 3. is. a diagrammatic and schematic perspective representation of the embodiment of fret control, string pluck control, and volume con-- trol incorporated in the instrument. shown in Figs. 1 and 2-;

Fig. 4 is a diagrammatic; representation of the, operation of the actuating or plucking member used in the instrument made in accordance with Figs. 1, 2 and 3,;

Fig. 5 is an enlarged view of a detail;

i 6 s a part ally o way fra t on pl view, on a, lar er s ale, an example o he key control device made in accordance with my invention; i

i 7 is a idevi w of; h de i e F with par s broken away nd n e t on h tails and;

Figs, 8; and 9-shown in a more or; less. diagramg matic manner; a. modification of the string pluck and volume control.

Like parts are numbered alike throughout the several figures of drawings. Details which may be presumed to b e, well known are described only to the extent required for conveying an under standing oithe invention. The drawings are not to. scale, and as a matter of fact, some details inseveral of the views are distorted at the expense' of other details, for the purpose of bringing out more clearly the essential structures of part Numeral II; in Figs. 1 and 2 indicates the finger-board of the instrument, and numeral |;2 the soundbox. As shown, the instrument is provided with six strings. There are seven frets on the finger-board, two being shown at I3 and NY in Figs. 1 and 2. In these views, the remaining five frets are covered up by the key control device I5. It; will be seen that this device carries rows of keys for each string, that is, in the present case, seven keys for each string, disposed gene erally' above the corresponding string and aligned therewith. There are thus seven-timesvsix keys, oratotal of forty-two. keys. The number of frets, strings and keys, shown is illustrative only, because the number of such elements may vary. Each key is downwardly movable for the purpose of depressing the corresponding string against the fret underneath each key. This operation determines the, note to be produced by plucking the corresponding string at the soundboard of box la. The depressiQI- of one of the keys also imparts a sliding motion to an operating bar slidably disposed under each lengthwise row of keys, which sliding motion is imparted to a rod l6 (Fig. 2) terminating in the string pluck device ll disposed on the sound box 12. The slidable operating members and their connecting rods it are omitted in Fig. l, in order to avoid obscuring the drawing.

The actuation of the slidable member by one of the keys, as described above, causes operation of a string-plucking means, provided for the corresponding string and disposed within the plucking device comprising the box IT, to produce the sound in accordance with the note set by the key depressed on the finger-board. The box I! of the string-plucking device is shown open in the drawings, but may, of course, be provided with a suitable cover. The string fret control device I is attached to the finger-board H by mean of suitable legs [8 and i9, and the box I! of the string-plucking device may be suitably attached to the sound box l2, for example, by means of the flanges and 2| The volume control includes a rotatably mounted rod I31 which may be angularly displaced by the operation of the lever I35 responsive to depression of the chin plate I44.

The hook I33 (Fig. 2) is provided for supporting the instrument on the shoulder, e. g., the right shoulder of the player.

Additional details of the mechanism in accordance with this embodiment of the invention are described below with reference to Fig. 3.

Numeral 22, in Fig. 3, shows a bar made of light-weight material and carrying a number of lateral projections 23. One such bar is provided for each string, and one projection for each key in the row of seven keys for each string. Inasmuch as it has been assumed that there are seven keys for each string, there are therefore seven such lateral projections carried by each of the slidable members or bars 22. Each bar is slidably mounted by members shown as pins 24, two such pins being indicated at each end of the bar 22. As will be explained presently, these pins may be ordinary screws attached in threaded connection underneath the top plate 55 of the key control device l5. Two keys and 26 are shown in Fig. 3. The key 25 is shown in normal retracted position, and the key 26 in depressed position, pressing the string 21 against the fret 28, thus setting the note to be produced by plucking the string 21 at its right end. The key 25, being retracted, has no effect on the strin 21 which lies above the fret 29. The remaining keys in the row are likewise in normal position.

Each key is provided with a plunger, as indicated at and 3|, and each plunger at its lower end carries an elastic member such as 32, 33, respectively, for contact with the string. The elastic member at the bottom of each plunger may be made of rubber. The fret control therefore produces a soft touch which imitates the touch of a players fingers.

Each key is rotatably mounted, as schematically indicated in Fig. 3, numeral at 25a and 26a, respectively, and carries a downwardly projecting nose or extension adapted to contact the corresponding lateral projection such as 23 extending from the coasting bar 22. It follows, therefore, that the bar 22 is displaced in a, sliding motion from right to left, as shown in Fig, 3, incident to depression of a key. In other words, the depression of any of the keys produces two operations, namely, the strin is placed in elastic contact with a fret and the bar 22 coacting with the keys in the string row is moved to the left.

Each member or bar 22 is suitably coupled with a connecting rod I6 which extends through an opening I Go in the forward wall of the housing I! of the string pluck control device. The end of each connecting rod l6, which is disposed within the box I1, i pivotally coupled, as indicated at 35a, with a wing 35 of a member 36 which in turn is rotatably mounted on a shaft 31 as indicated at 31a. The structure is particularly apparent from Figs. 3 and 5. There are mounted on the shaft 31 as many such members 36 as there are strings. In the present case, there being six strings on the instrument, there are six such members 36 rotatably mounted on the shaft 31. The wing 35 of each of these members is biased in clockwise direction by a sprin 38 which is adjustably secured in the rearward wall of the box 11, and the tension of which is adjustable by means of a screw 39. The structure exerts a normal pull on the connecting rod [6 and therefore on the slidably mounted member 22 carrying the projections 23 at the finger-board of the instrument. The sliding displacement of the member 22 by the depression of one of the keys in the string row therefore is against the pull of the spring 38.

The mechanism in the string-plucking device H is shown in normal position in which it is when the keys are in normal or retracted position. It may be mentioned at this point that each of the members 35 is provided on each side with an extension such as 40 shown in Fig, 5 for the purpose of spacing each of these members with respect to the adjacent members on the shaft 31. The extensions 40 may be ordinary spacing washers.

The member 36 is also provided with a downwardly extending wing 4| which carries a threaded shaft 42. The right end of this threaded shaft carries a. counterweight 43, and the left end carries an elastic plucking member 44 which may be made of rubber. This member is provided with a downwardly projecting camshaped extension, as shown, and a laterally extending arm 45 which is movable between two fixed pins 46 and 41. Each of these elastic plucking members is mounted on its corresponding shaft 42 in frictional rotatable engagement therewith. The mounting means may include suitable nuts and washers at the end of the shaft 42 for holding the elastic plucking member thereon.

When the member 36 is angularly displaced in counterclockwise direction consequent to the pull of the connecting rod I6, upon sliding displacement from right to left of the member 22, in response to the depression of one of the keys, the arm or rod 42 carried by the win 4| of the member 36 will be displaced in counter-clockwise direction, moving the elastic actuating member 44 downwardly in the direction of the string 21 and displacing the counterweight 43 upwardly. This downward movement produces the plucking of the string selected by the depressed key, thereby producing the note set by contact of the elastic member such as 32 or 33 with the string and the corresponding fret. The counterweight produces a certain modulation of the volume in accordance with the speed of displacement which is a function of the speed and force Of depression of the key and by its momentum assures proper plucking. The plucking operation of this embodiment is best described with reference to Fig. 4, which includes five diagrammatic views numbered IV, inclusive.

Referring now to Fig. 4, diagram I, it will be seen that the elastic actuating or plucking member 44 is in normal position, as also shown in Fig. 3, with the arm 45 approximately in contact with the stationary pin .46. The string to be plucked is indicated at 21 and the string adjacent thereto is indicated at 50. Numeral 41 indicatesthe stationary pin provided for coaction with the arm 45 of the elastic plucking member.

, Upon depression of one of the keys, the slidable member such as 22 is moved from right to leftjas previously described, pulling the connecting rod' IS with it, and thereby tilting the member 36 in counter-clockwise direction, causing angular counter-clockwise displacement of the rod 42 and consequently downward motion ofthe elastic plucking member 44 in a direction substantially perpendicular to the string 21. 'The member is thus brought into position II shown in Fig- 4. The force of this downward motion will depend on the force applied to the key. The motionmay be relativelygradual or it may be sudden. In the position II, the arm 45 contacts the stationary pin 41. Further downward displacement of the rod42 brings the elastic plucking member 44 into position III, this member rotatin or tilting on its shaft 42 in counterclockwise direction, because the arm 45 engages the stationary pin 41. As the member 44 rotates from the position IIinto position III, the tip of its downwardly depending nose or cam extension comes into contact with the string 21, and plucks the string in passing it to reach its position III. The downward motion and the angular motion imparted to the plucking member 44, as illustrated in diagrams II and III, thus produces the plucking of the string 21 in imitation of the plucking which maybe produced by the fingers of a player. This pluckingwill be relatively soft or sudden depending on the force applied in depressing the key, producing a correspondingly modulated sound. The force of the counter-weight assures such action and also assures. the downward motion of the plucking member from position II to position III. When the elastic pluckin member 44 reaches its lowermost position, indicated in diagram III of Fig. 4, its downwardly depending plucking nose or cam-shaped extension is placed into a position away from the string 21.

The restoring motion now follows in accordance with the diagram IV of Fig. 4. The rod 42 moves angularly in clockwise direction as seen in Fig. 3, and the elastic plucking member 44 therefore moves upwardly, out of contact with the string 21, and its lateral arm 45 contacts the uppermost stationary pin 46 which may be termed the restoring pin (while the lowermost stationary pin 41 may be termed the escape pin). Further upward motion of the rod 42 into its normal position shown in Fig. 3 restores the member 44 to the normal position shown in diagram V of Fig. 4. The counterweight assists the restoring motion of the device.

It will be seen from the above description that the elastic plucking member 44 is actuated in the manner of an escapement.

The volume may be additionally controlled by the player by means of the chin-operated member I44. When this member is depressed,

it displaces the lever I35 angularly, thereby rotating the rod I31 which is mounted in journal brackets suchas I35. These brackets may be suitably secured, one on the side wall of the keyboard l5 and another on the side wall of the box 11. The rotation of the rod l3! causes angular (iii displacement of the pins I38, I39 (Fig. 3) against the washer or head I46 carried on the end of the shaft 31, tending to move the shaft 3! axially. The shaft may be mounted for axial displacement as shown in connection with the embodiment i1- lustrated in Fig. 9. All the bracket members 36 and therewith all the elastic plucking members 44 are thus shifted in a direction away from their corresponding strings. The maximum shifting motion that is required may be very small, about 19:", in order to produce the described volume control. Maximum plucking volume is obtained with the mechanism in the normal position shown, that is, with the chin control in nonoperated position. More or less depression of the chin lever within the small range indicated causes corresponding diminution of the volume.

Figs. 6 and 7 are particularly directed to the structure of the keys and the mounting thereof. Numeral indicates the top plate of the key control device. This top plate is provided with longitudinal slots 5660 disposed in a transverse row in alignment with the fret 6 I. A similar transverse row of slots 62-66 is in alignment with the fret 61; and a like transverse row of slots is provided for the frets 68 and 69, respectively,

and, of course, for each one of the remaining frets. Viewing the structure in longitudinal direction, there are therefore as many slots for each string as there are frets on the finger-board of theinstrument. The right end of each slot is provided with a circular enlargement for receiving and guiding, the plunger of the corresponding key which is pivotally mounted in each slot.

.As will be apparent from Figs. 6 and 7, each key comprises an operating member indicated at Ht-l3, each such operating member being made of flat stamped material. Each member is pivotally mounted in its corresponding slot on pins such as 15 and 16, as indicated in connection with the operating members 10 and TI. The operating member 12 is likewise pivotally secured on a pin such as 80, and the member 13 on a pin 8|. The pivotal mountings l5, 16, 80, 8| for the keys 10, H, 12, 13, respectively, correspond to the pivotal mountings 25a, and 260, shown in Fig. 3 in connection with the keys 2 and 26, respectively. Each key carries a curved top member, as shown, which is suitably shaped for easy operation by the player. The key 10 is held in normal retracted position by a spring 82 and the key H is held in such normal position by a spring 83. A similar spring is, of course, provided for each of the remainin keys. The keys are shown arranged in a common plane. If desired, the rows of keys may be staggered in transverse direction, the keys in the center occupying a higher position than those at the edges.

Each operating member 10-13 carries at its forward end a slot such as 85 indicated in connection with the key 13 for pivotal engagement with a pin 86 which bridges a slot 81 in the plunger 88. The slotted forward end of each key is inserted in the slot such as 81 of its corresponding plunger. The lower end of each plunger is recessed, as shown in connection withthe plunger 98, and carries an elastic member such as 9| for contact with the string and the fret. The elastic contact imitates the touch of a player. Each plunger or key may be provided with a suitable stop for limiting the restoring motion thereof.

Numeral is in Figs. 6 and 7 indicates the leg for mounting the fret control device, also shown in Fig. 2.

The notched bar underneath the row of keys which actuates the corresponding plucking member is indicated in Fig. 7 by numeral 22. The projections 23 on this bar are contacted by the depending extensions of the keys, as previously described. Each bar is slidably mounted by means of screws 24a which correspond to the pins 24 shown in Fig. 3. Suitable stop means may be provided for limiting the sliding displacement of each of the bars 22.

A modification of the invention is diagrammatically indicated in Figs. 8 and 9, which will be described next.

These figures show four strings IOU-I03. The number of strings may, of course, vary. The key and fret control coacting with this modification may be made along the lines described in connection with the previous figures. Accordingly, there is a connecting rod IGa (Fig. 8) which corresponds to the connecting rod I6 shown in Figs. 2, 3 and 5. This connecting rod is pivotally secured in connection with an arm I04 carrying a counterweight I05 and a member which may be rotatably mounted thereon for engagement, in the nature of a pawl member, with certain plucking means on the disk I06. The connecting rod IGa, and therewith the arm I04, are held in normal retracted position; that is, they are biased in clockwise direction by a spring 38a which corresponds to the spring 38 in Figs. 3 and 5. This spring may be adjustably mounted in the manner previously described.

Upon angular displacement in counter-clockwise direction, as seen in Fig. 8, the arm I04 is adapted to rotate the disk I06 by means of its pawl member, shown in engagement with a plucking member I I I. There is one such disk provided for each string and each disk is rotatably mounted upon a shaft 31a which corresponds to the shaft 31 shown in Figs. 3 and 5, with the difference that shaft 31a is mounted at an angle, placing the disk I08 at an angle between adjacent strings, e. g., between the strings I and IOI. Therefore, a similar disk I06 will be angularly disposed between the strings IOI and I02, another between the strings I02 and I03, and so on, as many disks as there are strings on the instrument. The angle at which the shaft 31a is disposed is somewhat exaggerated; the inclination of the disks therefore may be smaller in practice than that shown in Fig. 9. Each disk is provided on one side with a number of elastic actuating or plucking members which may be made of rubber and suitably attached to the disk, such members being indicated at IIOIII. In other words, there are eight such cam-shaped elastic plucking members on each disk. These plucking members also operate in the manner of a ratchet in coaction with the pawl member on the arm I 04. The connecting rod I6a and the arm I04 with its pawl, and counterweight I are not shown in Fig. 9, in order to avoid confusing the drawing.

When the connecting rod I6a is displaced responsive to the depression of one of the fret control keys, as previously described, it actuates the arm I04 and displaces it angularly, as seen in Fig. 8, in counter-clockwise direction by 45, thus rotating the disk one-eighth of a revolution by means of the pawl member which is shown in engagement with the plucking member III now acting in the nature of a ratchet tooth, A detent I20 is provided for coaction with the plucking members acting as ratchet elements in order to prevent clockwise rotation of the disk I06. The angular one-eighth of a revolution displacement of the disk moves the elastic plucking member I I3 into the position in which the plucking member H4 is shown in Fig. 8. Member I I3 therefore passes the string I 00 and plucks it, producing the sound according to the note set by the fret control key. The action is thus similar to the action of the plucking member, e. g., member 44-45, described previously with reference to Figs. 3 and 4. The action of the counterweight I05 produces a volume modulation in accordance with the force applied in depressing a key, as previously described. The disk I00 locks now, by engagement of the detent I20 with the plucking member II! which has advanced to the position in which member H6 is shown in the drawing. The arm I04 returns to its normal position shown in Fig. 8, and its pawl member by-passes the plucking member IIO which has advanced to the position in which the plucking member II I is shown, looking behind it. The mechanism is again in the position shown in Fig. 8, with the disk and its plucking members angularly displaced by 45, or one-eighth of a revolution. Double plucking of the string is prevented incident to the counterclockwise motion of the plucking members, which is due to the suitably angularly tilted position of the shaft and the disks, as shown in Fig. 9.

As in the previously described embodiment, the volume may in this instance be additionally modulated or controlled by axial displacement of the shaft 31a and the disks thereon. The shaft is mounted, in suitable journals in the box walls IT, for axial displacement, and may be held in a normal position by means of a spring I43, disposed in a. housing extension I, and acting against the head I42 on the end of the shaft 31a. Accordingly, when the chin lever such as I35 in Figs. 1 and 3 is depressed, the shaft or rod I 31a will be rotated to press the pins I39a and I 30a, shown in Fig. 9, against the head or washer I40a carried by the shaft 31a, thereby shifting the shaft 31a, and with it the disks such as I06 and the plucking members thereon, also the actuating arms, in axial direction, away from the corresponding strings. The motion required is relatively small, at the most about 3 as in the previously described embodiment, and does not interfere with the functioning of the mechanism. The volume of the sounds produced may thus be selectively diminished by the operation of the chin-controlled plate II4 shown in Figs. 1 and 3, in a similar manner as described in connection with the embodiment shown in the other figures.

It is clear, of course, that the volume control has been shown and described as including a chin-operated element only for the sake of convenience. Such element may likewise be controlled by a foot-operated treadle or the like.

The embodiment according to Figs. 8 and 9 may be mounted on the instrument in a similar manner as the previously described structure, preferably directly above the central opening which is usually provided on the soundboard of the instrument.

The invention is particularly intended for producing sound by plucking strings in imitation of the fingers of a player. Nevertheless, the invcntion may also be used for producing a hammer or hammer-like string-picking or by-pass action, that is to say, by angularly displacing a hammer element in momentary contact or in picking bypass contact witha string. This may be done by pivotally mounting one end of a lever carrying a hammer or string-picking element, for example, at the rearward end of the top plate of the finger-- board, one such lever and element for each of the corresponding string is depressed, theimember such as 2;; will move, frcmrleft torightjand will tiltthe lever carrying, the string-picking element inclockwise direction, producing the desired hammer or string-picking action.

The fret control members have been shown directly above and inperpendicular alignment with their frets. This has been donemerely for the sake of convenienca as these niembers may in practice be positioned somewhat in back of the frets, i. e., somewhat at the left of the fretsas viewed, for example in Fig. '7. Th plucking members as well as the f etcontrol inserts may be made of rubbergas stated, or of anysuitable a d desirable? bia ere ly. las c. or .fibrousyieldable, or porous mater al adapted to produce the desiredtouch imitating finger action. The volume control may operate to increase or to' decrease theivolume, as desired, simply by providin tr e i placemen o theyp u n m m rs ie 'e ih Stripes. '0

Changes and modifications is possible Within the scope and spirit of the appended claims,

holding such string in engagement with the corresponding fret, a string plucking device disposed on the-soundboard of said instrument and comprising a plucking member for each string, and

.means actuated responsive to the operationof a key for operating the plucking member to vibrate the string held in engagement with the fret selected by the key which has been actuated on said fret control device; i

4. The structure defined in, claim 3,, together witlr a string plucking device disposed on the so dboard of said instrument and comprising a plucking member for each string, and means actuated responsiveto the operation of a key for operating the plucking member to vibrate .the string held in engagement with the fret selected bythekey which has been actuated on said fret control device, said last named means comprising a member mounted generally in parallel with the string which is to be .plucked, means. operated incidenttotheactuation ofa key for shifting such member, an operating, member angularly displaced by such member, and means actuated bytheoperating member for moving the plucking member to pluck said string,

:5 Thestructure. defined in claim: 3, together with astring plucking device "for coaction with the soundboard of said instrument and com-1 prising an elastic plucking member for each string, and means actuated responsive to the operation of a; key, for operating the plucking member to vibrate the string held in engagement with the fret selected bysuch key, said last named iiicans comprising-a,rod-like member disposed wherein I have defined what I believe is new and desire to have protected by Letters Patent of the United States.

I claim:

1. In a stringed instrument having a fingerboard at one end and a soundboard at the other end, a fret control device coacting with said finger-board, said device comprising a mounting member secured to said finger-board and forming a keyboard thereon which extends across the finger-board on top thereof, a plurality of sets of keys carried by said keyboard each set having a number of keys for each string corresponding to the number of frets provided for such string, a plunger operable by each key, means for pivotally mounting each of said keys in said keyboard at a point spaced from the axis of its plunger, and means for pivotally connecting each key with its plunger so as to move such plunger responsive to the action of the key perpendicularly toward its string for holding such string in engagement with the corresponding fret.

2. The structure defined in claim 1, together with an elastic actuating member carried by each plunger for elastically contacting the string and placing such string in elastic engagement with the fret.

3. In a stringed instrument having a fingerboard at one end and a soundboard at the other end, a fret control device coacting with said finger-board, said device comprising for each string a plurality of keys corresponding to the number of frets provided for such string, a plunger operable by each key, means for pivotally mounting each of said keys at a point spaced from the axis of its plunger, means for pivotally connecting each key with its plunger so as to move such plunger responsive to the actuation of the key perpendicularly toward its string for generally in parallelwith the string to be plucked,- means operated incident to the actuation of a key for shifting such rod-like member, an operating member angularly displaced by the rod-like member, and means actuated by the operating member to move the elastic plucking member for elastically'plucking said string.

6. The structure defined in claim 3, together with a string plucking device for coaction with the soundboard of said instrument and comprising a. plucking member for each string, said plucking device comprising a pivotally mounted lever arm, an elastic string plucking member carried by said lever arm, and means actuated incident to the operation of a key for angularly displacing said lever arm to move said plucking member into contact with the string selected by such key.

7. The structure defined in claim 3, together with a string plucking device comprising a plvotally mounted lever arm, an elastic plucking member carried by said lever arm, means actuated incident to the operation of a key for angularly displacing said lever arm to move said plucking member so as to pluck the string selected by such key, and a counterweight carried by said lever arm for controlling the action of said plucking member.

8. The structure defined in claim 3, together with a string plucking device comprising a, pivotally mounted plucking member, and means actuated incident to the operation of a key for angularly displacing said plucking member so as to pluck the string selected by such key.

9. The structure defined in claim 3, together with a string plucking device comprising a pivotally mounted plucking member, means actuated incident to the operation of a key for angularly displacin said plucking member so as to pluck the string selected by such key, and volume control means for variably adjusting the position of said plucking member with respect to the posi tiOn of the string so as to determine the plucking contact thereof with such string.

10. The structure defined in claim 3, together with a string plucking device comprising a. pivotally mounted plucking member, means actuated incident to the operation of a key for angularly displacing said plucking member so as to pluck the string selected by such key, and volume control means comprising a counterweight for said plucking member to govern the force of plucking contact thereof with said string.

11. The structure defined in claim 3, together with a string plucking device, comprising a rotatably mounted arm, an elastic plucking member carried by said arm, means controlled by any one of the keys associated with one of said strings for rotating said arm to efiect plucking engagement of said plucking member with a string, and stop means for controlling the actuation of said plucking member with respect to said string.

12. The structure defined in claim 3, together with a string plucking device comprising 9. rtatably mounted disk, elastic plucking members carried by said disk at one side thereof, and means controlled by any one of the keys associated with one of said strings for rotating said the string selected by the actuation of a key, and means operatively controlled by the operation of a key for actuating the plucking member associated with the corresponding string.

14. The structure defined in'claim 13, together with means for selectively adjusting the position of said plucking member with respect to the string coacting therewith to control the sound volume produced by engagement of such plucking member with the string.

15. The structure defined in claim 13, wherein a rotatably mounted disk carrying a plurality of plucking elements constitutes said plucking member.

16. The structure defined in claim 13, wherein a rotatably mounted lever arm carrying a plucking element constitutes said plucking member.

ROBERT RUF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 680,485 Hochspeier Aug. 13, 1901 1,420,784 Szyslak June 27, 1922 10,213 Robertson Nov. 8, 1853 957,681 John May 10, 1910 389,137 Crawford Sept. 4, 1888 1,946,827 Bach Feb. 13, 1934 1,797,609 Hallbauer Mar. 24, 1931 738,018 Farago et al Sept. 1, 1903 637,273 Miller Nov. 21, 1899 1,266,314 Quemore May 14, 1918 

